DE2424457A1 - METHOD AND DEVICE FOR ADJUSTING A PHOTOELECTRIC READING DEVICE FOR WEB CARDS - Google Patents

Description

Verdol S.A., Caluire (Rhone), France

Method and device for adjusting a photoelectric reading device for web cards

The invention relates to a method for the automatic adjustment of a successive weft rows of the network of lines intended for the photoelectric reading of web cards
the card scanning reading device in the chain direction from one to the next row of wefts as well as a device suitable for carrying out such a method.

It is known to apply the patterns to be reproduced in patterned fabrics beforehand in multiple colors on a checkered paper on a large scale in order to obtain a map in which the rows of rectangles of the paper running in one direction correspond to the weft threads of the fabric and the rows of rectangles running in the other direction correspond to the warp threads. According to the classic procedure, the. card thus obtained arranged for reading from the card racket that the corresponding wefts are hori- rows ¹ right. Starting from the top, the card racket moves
then follow these rows one after the other from left to right.,

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at the same time the punch depending on the in each case available colors actuated. Recently, the card racket has been replaced by photoelectric readers recognize the colors automatically and the punch accordingly steer. In reading devices of this type, the horizontal arrangement of the rows corresponding to the weft threads is Rectangles no longer of interest; you can just take a series of shots and chains speak to remind people that in in practice, the reading device reads the successive rows of shots and means are provided to ensure that the color is read in the center of each rectangle. For For this purpose, an auxiliary device can be provided which is offset by half a step with respect to the main device and which is operated in such a way that it only recognizes the lines of the line network running in the chain direction. if the last rectangle of a row of wefts is read, the overall arrangement of the reading device becomes the beginning of the following row of wefts brought back, whereby a relative adjustment takes place in the chain direction, which is equal to the size of a row of wefts.,

The postponement corresponding to the provision does not make any Trouble. For this purpose, you can use the drive motor of the reading device with reference to the card (or vice versa the Drive motor for the card with respect to the reading device) run backwards; but it is also possible, for example; to place the card on a drum that rotates in such a way that that after overflowing one edge of the card, the reading device

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device automatically reaches the other edge without running backwards is required. However, the adjustment from one row to the next is associated with certain difficulties.

One cannot be satisfied with the reading device mechanically to adjust a predetermined size, because the paper of the card is sensitive to moisture, so that the size concerned would have to be determined each time with high accuracy, which is very would be complicated. One could think of providing an auxiliary cell in this case too, around one in the chain direction is arranged offset by half a step and by means of which the lines of the line network running in the weft direction can be recognized permit. However, if the division is used for such cards Papers is practically constant in the weft direction, this does not apply to the pitch in the warp direction. at With such a solution, the offset of the auxiliary system in relation to the main system must therefore be reset each time, which is not very difficult in principle, but in practice a lengthy work process that can lead to errors or omissions.

According to the invention, the reading device is below in the chain direction adjusted to the influence of an electric stepper motor, in particular by appropriate design of the reduction between the motor and the reading device ensures that the partial displacement of the reading device corresponding to each step of the motor smaller than the tolerance of the centering of the reading

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device on the card is in the chain direction; further will the stepping motor controlled by means of a series of electrical pulses so that it is at the end of a predetermined. number of impulses by one step at a time in the forward direction drer ^ - the total number of pulses required is counted by means of the stepping motor to move the reading device from the axis of the outer row of the cap to the axis of the other outer row To get a series of shots; with formation of an integer quotient, the total number thus obtained is replaced by the Number of rows of shots reduced by one divided; to adjust the reading device after scanning a series of shots emitted a number of engine control pulses that is equal to the quotient found in this way.

If the number of pulses corresponding to one step of the stepping motor is selected to be sufficiently large, that of the The quotient of permissible errors is negligibly small, even if one takes into account that this error adds up, because it repeats itself from one series of shots to the next each time the reading device is adjusted. The bug attributed to it is that the shift caused by a step of the stepping motor is not divisible, does not add up to + so that it is enough to make the displacement smaller than the allowable tolerance of the centering.

The device for carrying out the above-mentioned method preferably has a device that during a

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Preparatory phase lets the reading device run from one to the other outer row of shots, a counter that counts the total number of pulses emitted during the preparatory phase, a device that records an indication of the number of rows of shots on the card reduced by one and divides by the total number of pulses mentioned, and a device _{which responds to r} during the reading of the card when the reading device has reached the end of a series of wefts and displaces the reading device in the chain direction by a distance which corresponds to a number of pulses equal to said quotient.

Embodiments of the invention are shown in the drawing and are described in more detail below. Show it:

Fig. 1 is a schematic perspective illustration of a first embodiment of a device for photoelectric Reading a web map,

Fig. 2 is an elevation of a second embodiment and

3 shows an electrical circuit diagram for an embodiment a circuit arrangement suitable for carrying out the invention.

In Fig. 1, a reading device for a web map is shown, which has a drum 1 on which the card 2 is arranged

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net is that their rows of shots perpendicular to the shaft 3 of the drum

get lost. In front of the drum is a guide 4, ajf de ^r a reading device 5 can be adjusted, which has a certain number of photoelectric cells to which suitable color selection devices are assigned. The reading device 5 can optionally also be equipped with an auxiliary cell for reading the chain lines on the card and further auxiliary devices. The reading device is connected to a circuit arrangement of a known type via flexible lines 6. The reading device is displaced, for example, by means of a screw spindle 7 which is connected via a gear 8 to a motor 9, which ensures that the reading device 5 is moved from one row to the next.

The drum 1 rotates constantly in such a way that after "passing the lower longitudinal edge of the card 2 the reading device 5 again comes to lie opposite the upper longitudinal edge of the card without having to switch to reverse. In the meantime however, the screw spindle 7 must rotate through such an angle that the reading device 5 in the longitudinal direction, i. H. in the direction of the chain to adjust the size of a row of shots on the card.

Fig. 2 shows another possible embodiment as a further embodiment mechanical solution. The card 2 is fastened flat on a suitable plate 10. This plate is driven by carriage 11 carried, which are moved on lateral guide rods 12

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can. Each of the two carriages is driven by a screw spindle 13 powered. The two screw spindles are above a chain 14 in connection with one another. One of the two screw spindles is driven via a reduction gear 15; its drive shaft in turn to an appropriate one Electric motor is coupled. The reading device 5 sits on a guide 4 and is on this by means of a screw spindle 7 adjustment, which via a gear 8 by means of a motor 9 is driven. The rows of shots of the card 2 run parallel to the screw spindles 13, which in this way for scanning of the series of shots. After reading a series of shots, the guide 4 must be reset for reading the following series of shots will.

In either case, the electric motor 9 is a stepping motor, that is to say a motor which continues to run through a predetermined angle for each electrical signal of sufficient voltage and current strength supplied to it. This angular step of the motor 9 and the reduction ratio of the gear 8 are selected so that the relative adjustment of the reading device 5 with respect to the card 2 in the chain direction due to such a motor step is well below the closest centering tolerance that the reading device with reference to the Card in the mentioned direction is desired. In other words, if the motor continues to run by one step _f after the reading device 5 is already almost opposite the axis of a row of shots, the reading process is no less accurate

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correctly.

The circuit arrangement according to FIG. 3 has a pulse generator 16, which hereinafter designates a sequence of primary pulses emits neten "pulses with a relatively high pulse repetition frequency, the output 17 of the pulse generator is connected to one input 18 or 19 of the two inputs of AND circuits 20, 21 connected, the outputs 22, 23 of which are each connected to one of the inputs 24, 25 of an OR circuit 26 are connected. The output 27 of the OR circuit is connected to the input 28 of a first Counter or feed counter 29 connected. This counter is designed as a ring counter, i. H. he counts a certain number of Pulses and then jumps back to zero to start counting again. The number of pulses for which the counter 29 is designed, is referred to here with η. Every time the counter jumps from η to zero, the counter gives one Output 30 from a pulse, which is hereinafter referred to as a secondary pulse and which is fed to the motor 9 to this to advance one step.

The direction of rotation of the motor 9 is determined via two lines 31 and 32, which cause the motor to be recorded during each of it Secondary pulse runs forwards or backwards. The reverse line 32, which is normally used while reading a The series of shots is not used, is via a manually operated button 34 (reverse button) with a supply voltage connection 33 tied together. The part of the line 32 behind the key

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is connected to the second input 36 of the AND circuit 20 via a line 35. The forward line 32 takes the current from the output 37 of a first bistable storage stage, e.g. B. a flip-flop, 38 on; it is connected to the second input 40 of the AND circuit 21 via a line 39. The memory stage 38 is provided with two control inputs 41 and 42. The first of these inputs receives an end-of-row signal when the reading device 5 has read the last rectangle of a row of wefts. In the case of the embodiment according to FIG. 1, there is no need to reset the reading device 5; the aforementioned signal can be triggered by the drum 1 itself or by a cam assigned to this drum. In the embodiment according to FIG. 2, for example, the arrangement can be such that after a row of shots has been read, the reading device advances further and triggers a contact device or an equivalent stage which provides for the reset and at the same time allows the signal to go to input 41. Regardless of how the design is made in detail, the storage stage 38 emits an output signal under the influence of this signal, by means of which the motor 9 is switched to forward running. The second control input 42 is provided in order to reset the memory stage 38 to zero and in this way to put the motor out of operation, as will be explained in more detail below.

A second counter 43 or row counter is also provided » the input 44 of which is parallel to the input of the feed counter 29. The output signal is from output 45 of this counter in

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In parallel form on the input 46 of a first comparator (program comparator) 47, which is equipped with suitable means _r, for example switches, which allow any desired number to be stored, which is to be used as a basis for the comparison with the content of the counter 43. If this counter content is equal to the number stored in this way, the comparator 47 outputs a signal to an output 48 which is connected to one input 49 of an AND circuit 50, the output 51 via a line 52 to the input 53 of a third counter or quotient counter 54 is connected. The output 55 of this third counter and the output 45 of the second counter are connected in parallel via corresponding lines 56, 57 to an input 58 and 59 of a second comparator or divisor comparator 6O. If there is a match between the contents of the two counters 43 and 54, the comparator 60 emits a signal at its output 61 which is fed to one input 62 of an AND circuit 63. The second inputs 64, 65 of the AND circuits 50 and 63 are connected to one another via an inverter 66.

The circuit arrangement according to FIG. 3 also has two pushbuttons 67 and 68 (reset button and read button), which are connected via lines 69 and 7O each with an input 71, 72 of a second bistable memory stage (flip-flop) 73 are connected, the output 74 via a line 75 to the second input 65 of the AND circuit 63 and is connected to the second input 64 of the AND circuit 50 via the inverter 66. Line 69

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is also connected via a line 76 to a line 77, to the reset inputs 78 and 79 of the feed counter 29 and the quotient counter 54 is connected. The line 77 is also a three with the first input 80 Having inputs OR circuit 81 connected. The second Input 82 of the OR circuit 81 is connected via the line 52 to the output of the AND circuit 50, during the third input 83 is connected to a line 84, which in turn is connected to output 85 of AND circuit 63. The output 86 of the OR circuit 81 is connected to the reset input “87 of the counter 43.

Von.der connected to the output 85 of the AND circuit 63 line 84 a further line 88 goes off, which leads to the second input 42 of the first memory stage 38.

The circuit arrangement works as follows:

Assuming that the arrangement is at zero, as far as the counters 29, 43, 54 and the storage stages 38, 73 are concerned, the leads Operator in the course of the preparation phase in any appropriate manner the reading device to the intersection between the first row of chains and the last row of shots on the card. In addition, the operator counts the number N of Rectangles of each of the chain rows, if this number is not already known, and gives this number minus one, d. H. N - 1, via pushbuttons or the like in the program

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comparator 47 a. N represents the number of series of shots on the card represents, while N - 1 is equal to the number of partial adjustments is of the size of such a series of wefts that the reading device must perform to move from one outer row of shots to the other the map to run. Then the operator operates the backward button 34 and hold down that button. This has the effect that on the one hand the motor 9 via the line 32 to reverse is switched, and that on the other hand, the AND circuit 2O prepared or is unlocked in order to then allow the primary pulses of the pulse generator 16 to pass. These pulses run through the OR circuit 26 to the feed counter 29, which adds up the pulses Every time the number of primary pulses arriving in this way reaches the value η to which the counter is set, the counter jumps back to zero. He gives at his exit 30 emits a secondary pulse which causes the motor 9 to take a step in the reverse direction, i. H. in that direction, that of returning the reading device towards the first row of wefts along the first chain row of the card is equivalent to.

At the same time, the primary pulses coming from the output 27 of the OR circuit 26 also reach the input 44 of the row counter Every time their number reaches a value equal to N - 1, i. H. the number N of rows of shots on the card reduced by one, the program comparator 47 emits a signal at its output 48. Since the memory stage 73 is at 0, the output of the inverter is present on L; consequently, the AND circuit 50 is prepared to do the

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Let the signal of the comparator 47 pass. This signal arrives Via the line 52 to the quotient counter 54 and at the same time to the input 82 of the OR circuit 81. It runs through the OR circuit and in this way arrives at the reset input 87 of the counter 43, which consequently starts again with N-1 primary pulses to count, in order to let the quotient counter 54 advance again by one unit in this way. This work cycle repeats itself as long as the button 34 is kept closed. The divisor counter 6O remains inoperative during this working phase because that coming from its output 61 Signal the AND circuit 63 can not go through, the second input 65 as well as. the output 74 of the storage stage 73 is on O.

The operator releases the reverse button 34 and thereby interrupts the reverse movement of the reading device as soon as it reaches the axis of the first row of shots. If the total number of primary pulses emitted by the pulse generator 16 during this working phase is denoted by T, then the counter 54 has entered the quotient Q = T with an error.

N - 1

that corresponds to a remainder less than N - 1. In order to simplify the explanation, it can first be assumed be that this error is zero.

The operator then goes on to the actual reading phase. For this purpose, the push button 68 is first pressed,

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which has the consequence that the output 74 of the memory stage 73 jumps from O to L. As a result, the AND circuit 63 is at the input 65 prepared, while at the same time the AND circuit 50 at the input 64 via the inverter 66, which converts the L into O, is blocked. The reading device is then in the usual manner 5 according to Fig. 1 or 2 "along the first row of wefts Card 2 moved. The reader is at the end of the row 5 returned in the direction of the first chain row, either automatically in the case of the drum according to FIG. 1, or according to the embodiment according to FIG. 2 in the course of a return movement. At the same time, the end-of-row signal arrives at the input 41 of the first storage stage 38, during the preparation phase The output initially located on O now jumps to L. This has two consequences. For one thing, there is the engine switched to forward running via the line 31, while the line 32 is no longer connected to the supply voltage due to the release of the button 34. On the other hand, the AND circuit 21 is at the input 40 prepared, so that the primary pulses of the pulse generator 16, which are no longer sent via the AND circuit 20 to the OR circuit 26 can reach the OR circuit 26 via the AND circuit 21. The counter 29 takes its work again and lets the motor 9 advance in the normal running direction step by step, so that the reading device in the chain direction is adjusted from the first to the second row.

However, since the AND circuit 50 is blocked, the program comparator 47 cannot let the quotient counter 54 continue to run.

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sen. When the row counter 43 has received a number of pulses which is equal to the quotient Q = T stored in the counter 54, the divisor counter 6O N - 1 ·

output signal due to the unlocking of the AND circuit 63 via the line 84 to the input 83 of the OR circuit 81. The Signal runs through OR circuit 81 to counter 43 and sets this back to zero. At the same time, the signal reaches the storage stage 38 via line 88, which is set to O, whereby the transmission of primary pulses to the two counters 29 and 43 is interrupted. The motor 9 comes as a result to stop. He has adjusted the reading device by a distance that is equal to the center distance of the two rows of wefts, because its angle of rotation corresponds to the quotient between that for the total adjustment of the total number of primary pulses required from one to the other outer row of wefts and the number of rows reduced by one (i.e. N - 1), i.e. H. the number of adjustments of the size of a series of shots, which for the aforementioned total adjustment must be carried out.

The machine can now read the next row of shots. At the end of reading this series of shots, those described above run again Operations.

The arrangement described thus makes it possible to adjust the reading device automatically without having to worry about the division beforehand of the line network in the chain direction or around possible di-

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Changes in dimension of the map due to the humidity needs to take care of.

There are two factors to consider when it comes to the accuracy achieved. With regard to the quotient Q = T can

N - 1

on the one hand any desired accuracy can be achieved. That a very large number of primary pulses corresponding to one Step of the motor is selected. On the other hand, as far as the error is concerned, which is due to the fact that the adjustment caused by a step of the motor is not divisible, it is sufficient to ensure that this error is smaller than the tolerance of the centering. This does not cause any difficulties.

Numerous modifications are possible within the scope of the invention. For example, instead of counting the number N of rows of wefts, the number N 'of lines of the network of lines can be determined which are traversed by the reading device 5 while it is being moved from the first to the last row of wefts. Since N ¹ = N − 1, it can be avoided in this way that an inattentive operator omits the subtraction N − 1 and inputs the number N into the comparator 47 immediately.

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Claims (4)

242U57 Expectations (Λ . ^ A method for the automatic adjustment of a reading device which is intended for the photoelectric reading of woven cards and scans successive rows of wefts of the line network of the card in the warp direction from one to the next weft row, regardless of the line network division in the warp direction and of possible dimensional fluctuations of the card carrier, characterized in that the reading device is adjusted in the chain direction under the influence of an electric stepping motor, it being ensured that the partial displacement of the reading device corresponding to each step of the motor is smaller than the tolerance of the centering of the reading device on the card in the chain direction, dqß furthermore the stepping motor by means of a sequence is controlled by electrical pulses such that it rotates at the end of a predetermined number of pulses by one step in the forward direction, that the total number of pulses is counted, which is required by means of the stepping motor to let the reading device get from the axis of one outer row of shots of the card to the axis of the other outer row of shots, that the total number thus obtained is divided by the number of rows of shots reduced by one while forming an integer quotient, and that for adjusting the reading device after scanning a series of shots a number of motor control pulses is emitted, which is equal to the quotient thus found. 409850/0320 2. The method according to claim 1, characterized in that the a step of the stepping motor corresponding number of pulses is selected to be sufficiently large to the of the quotient approved, repeated with each adjustment of the reading device from one row of shots to the next and to keep corresponding cumulative errors negligibly small. 3. Apparatus for performing the method according to claim 1 or 2, characterized by a device which, during a preparatory phase, the reading device from the one to the other outer row of shots runs, a counter that shows the total number of shots fired during the preparation phase Impulse counts, a device that takes an indication of the number of rows of shots on the card minus one and divided by said total number of pulses, and means responsive while reading the card, when the reading device has reached the end of a series of wefts, and the reading device by a distance in the warp direction adjusted, which corresponds to a number of pulses equal to the quotient mentioned. 4. The device according to claim 3, characterized by a primary pulse generator, a feed counter, which receives the primary pulses, a signal or a secondary pulse for the indexing of the motor each time emits one step when the number of the primary pulses a correspondingly 409850/0320 - '19 - reaches the specified value, and which then jumps back to zero, to start the counting process again, a second counter (row counter), which also counts the primary pulses takes up a program comparator, on which the number of rows of shots of the card reduced by one adjustable and which is connected to the row counter in such a way that it emits a reset output signal each time when its content reaches the preset number, a third counter (quotient counter), which the output signal of the program comparator, a second comparator (divisor comparator), which contains the content of the row counter and of the quotient counter, a device that takes the divisor comparator out of operation during the preparatory phase sets, a device that puts the program comparator out of operation during the reading phase, and one through the output of the divisor comparator during the reading phase triggered device which stops the motor every time after the reader moves one row in the chain direction has adjusted. 409850/0320